Poly(arylene sulfide ketone), henceforth abbreviated as PASK, and poly(arylene sulfide diketone), henceforth abbreviated as PASDK, resins are engineering thermoplastics of potential commercial interest for film, fiber, molding, and/or composite applications because of their outstanding thermal and mechanical properties. General processes for the production of PASK and PASDK are known in the art. For example, PASK and PASDK can be prepared by the reaction of an alkali metal sulfide in a polar organic compound with a polyhaloaromatic ketone or a polyhaloaromatic diketone, respectively.
Disadvantages often associated with the production of PASK and PASDK resins pertain to the handling of the polymer produced. At the completion of a typical polymerization reaction, the reaction mixture is generally in the form of a slurry comprising a liquid phase (predominantly a polar organic compound and water) and a solid phase (predominantly polymeric resin), wherein the polymeric resin is in the form of powder-like particles when recovered. These recovered powder-like particles have very low bulk densities (e.g. generally less than 10 lbs/ft.sup.3 when dried). The slurry containing this extremely fine powder-like resin filters very slowly and thus hampers the polymer's washabiliiy, recoverability and processability. Washing, recovering and/or processing PASK and PASDK resins which have low bulk densities is extremely difficult.
One possible solution for improving the handling procedures of PASK and/or PASDK resins would be to employ a process which increases the resins' bulk density. While such a technique would be advantageous to the commercial industry, there are, however, some applications where such a technique would not be the most preferred mode for improving handling procedures. Specifically, in some commercial applications, it is necessary to have the PASK or PASDK resin in the form of a fine powder.
If a technique were employed which improved handling procedures by increasing the bulk density of the PASK or PASDK resins, and if these resins were to be employed in a process requiring the polymer to be in the form of a powder, the resulting resin would have to be milled or ground. Therefore, for those applications where it is desirable to use PASK or PASDK resins while in a powder form, it would be advantageous to improve the handling of the respective resins while not increasing their bulk densities.
Accordingly, one object of this invention to provide a method for preparing low bulk density polymers having associated therewith improved handling procedures.